Transformers are utilized as components of power supply networks. Transformers can be utilized for converting voltage from a first value at a high-voltage side to a second value, which is lower than the first value, at a low-voltage side.
The determination of properties of a transformer by means of a test in which one or multiple characteristic variables of the transformer are ascertained via measurement is required, for example, in order to ensure the operating safety, for the purpose of actuation, or for other reasons. Examples of such measurements include the determination of a static resistance, a transformation ratio, a leakage inductance or leakage reactance. Test devices for units used in power engineering can be designed not only for transformers but also for testing other units such as protective switches or protective relays.
Test devices can be configured for testing energy-related units such as transformers or converters that comprise an inductor. For example, such test devices can be configured for testing a transformer that includes an inductor in which energy is temporarily stored.
In different operating situations during a test of a test specimen, it can be desirable to reduce the energy stored in the inductor, for example to dissipate the energy. Examples of such operating situations include the end of a test of a test specimen or the end of a test step of a test procedure including several steps. Further examples include emergency shutoffs of the test device in the event of a fault.
One or multiple resistors can be utilized, for example, for reducing the energy stored in the inductor of the test specimen. Such techniques have the disadvantage, however, that the reduction of the energy stored in the coil can still take a relatively long time. This can be undesirable for different reasons. For example, it can be desirable for reasons of safety to reduce the energy stored in the inductor relatively rapidly.